Low temperature segmented copolymer compositions and methods

ABSTRACT

There is provided a method of synthesizing and using a segmented copolymer that includes mixing one or more α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminated polysiloxane first soft segments having an average molecular weight of between about 2500 grams per mole to about 10,000 grams per mole, and one or more diisocyanate species, together to form a first reaction product; mixing the first reaction product and one or more low molecular weight diol or diamine chain extenders each having an average molecular weight of less than 400 grams per mole, together in a solvent to form a segmented copolymer in solution; and applying the segmented copolymer in solution to one or more surfaces via spray coating directly from the solution with the segmented copolymer, wherein the segmented copolymer formed has a high flexibility at an environmental temperature of down to about −100 degrees Celsius.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application and claimspriority to pending application Ser. No. 14/602,279, filed Jan. 22,2015, now U.S. Pat. No. 9,388,272, issued Jul. 12, 2016, entitled LOWTEMPERATURE SEGMENTED COPOLYMER COMPOSITIONS AND METHODS, the entirecontents of which is incorporated herein by reference, which is adivisional application of and claims priority to application Ser. No.13/716,084, filed Dec. 14, 2012, now U.S. Pat. No. 8,957,175, issuedFeb. 17, 2015, entitled LOW TEMPERATURE SEGMENTED COPOLYMER COMPOSITIONSAND METHODS, the entire contents of which is incorporated herein byreference, which is a continuation-in-part application of and claimspriority to application Ser. No. 12/777,264, filed May 11, 2010, nowU.S. Pat. No. 8,334,356, issued Dec. 18, 2012, entitled LOW TEMPERATURESEGMENTED COPOLYMER COMPOSITIONS AND METHODS, the entire contents ofwhich is incorporated herein by reference.

BACKGROUND

1) Field of the Disclosure

The disclosure relates to segmented copolymers, and in particular, topolydimethylsiloxane (PDMS)-urethane/urea segmented copolymers.

2) Description of Related Art

Elastomeric materials are required in a broad variety of applicationsincluding use in low temperature environments. However, many knownelastomers do not maintain their advantageous elastic properties at lowtemperatures because such known elastomers may comprise polymer speciesthat cause the elastomers to stiffen and become brittle below theirglass transition temperatures (Tg). In addition, known polymers such aspolysiloxanes and polyfluoroethers that are able to individuallymaintain flexibility at low temperatures can have reduced mechanicalstrength at low temperatures.

Segmented polysiloxane-urea copolymers are known, such as thosedisclosed in U.S. Pat. No. 7,363,360 to Yilgor et al. However, Yilgor etal. requires that a polyether segment be incorporated between thesiloxane and urea hard segments in order to improve mechanicalproperties. Such an intermediate polyether segment introduces astructural element into the polymer system with a higher glasstransition temperature (Tg) of approximately −50° C. that can reduce thelow temperature range over which the material is elastic.

Elastomeric materials that possess the ability to demonstrate a highdegree of toughness through both high elongation and tensile strengthfind application in a variety of environments. One example of this isthe aerospace environment where low temperatures (less than −50° C.) arecommon. There is a need for materials that can maintain classic elasticproperties and continue to demonstrate high degrees of toughness inthese demanding environments. Many known elastomeric materials canundergo an abrupt increase in modulus of many orders of magnitudegreater than −50° C. as temperature is lowered. This is due to thepolymeric components that make up these materials possessing glasstransition temperatures above the environmental temperature where suchmaterials would find application.

It is desirable for elastomeric materials to be able to be formulatedinto a form that can be conveniently prepared and applied in the field.This can require precursor components that are capable of being storedand stable over acceptable time periods. Once activated, the elastomericmaterials may demonstrate an acceptable pot life or be suspended in amedium that allows for convenient application. Low general toxicity ofindividual components, chemical resistance to fluids commonly found inaerospace environments, and the ability to be compounded with fillermaterials are also desirable.

Elastomeric materials and systems typically have chains with highflexibility and low intermolecular interactions and either physical orchemical crosslinks to prevent flow of chains past one another when amaterial is stressed. For an elastomeric material or system todemonstrate good elastic behavior at low temperatures, it is desirablethat it be composed of elements that have low glass transitiontemperatures. Materials with low glass transition temperatures can havehighly flexible chains with less flexible interchain interactions.Examples of polymer materials that have low glass transitiontemperatures are PDMS and fluoroethers. However, these materials mayhave reduced mechanical properties due to the fact that they are wellabove their Tg under ambient conditions. In order to compensate forthis, silicone based materials and systems are known but may beformulated with fillers and heavily crosslinked to bring the mechanicalproperties of the final form to an acceptable level. Heavy crosslinkingin PDMS based materials and systems can result in an increase in Tg from−120° C. associated with the linear chains due to crystallizationeffects and narrowing of the low temperature range over which thematerial is elastic. Thus, an alternative method to covalentcrosslinking for reducing chain mobility in siloxane based elastomersystems is desired in order to maintain flexibility in these systems atlow temperature.

One known method available to produce a physically crosslinked elastomeris the use of segmented polyurethane or urea systems. These speciesdemonstrate strong hydrogen bonding potential between them and as aresult can create strong associative forces between the chains. In orderto produce elastomeric materials, regions of highly flexible and weaklyinteracting chains must be incorporated with strongly associatingelements. This can be accomplished using a segmented copolymerizationscheme. Segmented copolymers provide a straightforward synthetic routetoward block architectures using segments with vastly differingproperties. The end result of such synthesis are typically chains thatpossess alternating hard and soft segments composed of regions of highurethane bond density and the chosen soft segment component (e.g.,siloxane), respectively. This covalent linkage of dissimilar hard andsoft blocks drives the systems to microphase separation and createsregions of flexible soft blocks surrounding regions of hard blocks. Theassociative forces among the hard segments prevent flow under stress andcan produce elastomeric materials capable of displaying high elongationand tensile strength.

PDMS as a soft segment component in a segmented polyurethane urea systemfor an elastomeric material that demonstrates low glass transition isknown. In addition, silicone-urethane/urea systems are known. It isfurther known that differences in solubility parameter between PDMS andurea/urethane segments can provide a strong driving force towardmicrophase separation. Such sharp interfaces created in these materialscan result in low values of elongation and tensile strength. Knownmethods exist to reduce the sharpness of the transition between the hardand soft segments in siloxane-urea materials by incorporating a secondsoft segment that can act as an interface creating a gradient betweenthe two highly dissimilar materials. For example, polypropylene oxide(PPO) segments have been incorporated into segmented siloxane-ureamaterials in order to improve mechanical properties. However, while thePPO segments may increase tensile strength and elongation, the PPOintroduces a second glass transition temperature into the overallmaterial which can be much higher than the glass transition temperatureof PDMS greatly reducing the low temperature range over which thematerial is elastic.

Moreover, known filled elastomer based coatings, gap fillers andsealants can lack robust durability, especially under environmentalextremes such as low temperatures, (e.g., −50° C.).

Accordingly, there is a need for segmented elastomeric copolymercompositions and methods that provide advantages over known compositionsand methods.

SUMMARY

This need for segmented elastomeric copolymer compositions and methodsis satisfied. Unlike known segmented elastomeric copolymer compositionsand methods, embodiments of the segmented elastomeric copolymercompositions and methods provide numerous advantages discussed infurther detail in the below detailed description.

In an embodiment of the disclosure, there is provided a method ofsynthesizing a segmented copolymer. The method comprises mixing one ormore α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments having an average molecular weight ofbetween about 2500 grams per mole to about 10,000 grams per mole, andone or more diisocyanate species, together to form a first reactionproduct. The method further comprises mixing the first reaction product,and one or more low molecular weight diol or diamine chain extenderseach having an average molecular weight of less than 400 grams per mole,together in a solvent to form a segmented copolymer. The method furthercomprises removing the solvent. The segmented copolymer formed has ahigh flexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing a segmented copolymer. The method comprises mixing one ormore α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments having an average molecular weight ofbetween about 2500 grams per mole to about 10,000 grams per mole, andone or more diisocyanate species, together to form a first reactionproduct. The method further comprises mixing the first reaction productand one or more perfluoropolyether second soft segments together to forma second reaction product.

The method further comprises mixing the second reaction product and oneor more low molecular weight diol or diamine chain extenders each havingan average molecular weight of less than 400 grams per mole, together ina solvent to form a segmented copolymer. The method further comprisesremoving the solvent. The segmented copolymer formed has a highflexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing a segmented copolymer. The method comprises mixing one ormore α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments having an average molecular weight ofbetween about 2500 grams per mole to about 10,000 grams per mole, andone or more diisocyanate species, together to form a first reactionproduct. The method further comprises mixing the first reaction productand one or more second soft segments together to form a second reactionproduct, wherein the one or more second soft segments isperfluoropolyether; α,ω (alpha, omega) dihydroxy terminated fluoroether;α,ω (alpha, omega) hydroxyl terminated poly(perfluoromethylisopropylether); polythiodifluoromethylene; polybutadiene;polydioxypropylphosphazene; polydioxyethylphosphazene;polydioxymethylphosphazene; polyisoprene; or polyisobutylene.

The method further comprises mixing the second reaction product, and oneor more diamine chain extenders each having an average molecular weightof less than 400 grams per mole, together in a solvent to form asegmented copolymer, wherein the one or more diamine chain extenders isisophorone diamine (5-amino-1,3,3-trimethyl cyclohexanemethanamine);bis-(p-aminocyclohexyl)methane; 2,2-bis(4-aminocyclohexyl)propane;4-methyl-1,3-cyclohexane diamine; 2,4-diethyl-6-methylcyclohexane-1,3diamine; or a mixture of two or more thereof. The method furthercomprises removing the solvent. The segmented copolymer formed has ahigh flexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a segmentedcopolymer composition. The composition comprises one or more α,ω (alpha,omega) amine or α,ω (alpha, omega) hydroxyl terminated polysiloxanefirst soft segments having an average molecular weight of between about2500 grams per mole to about 10,000 grams per mole. The compositionfurther comprises one or more diisocyanate species. The compositionfurther comprises one or more low molecular weight diol or diamine chainextenders. The composition preferably has a high flexibility at anenvironmental temperature of down to about −100 degrees Celsius, andfurther has a percent elongation of greater than about 250%, a hightensile strength of greater than 25 MPa (megapascals), and a single lowglass transition temperature (Tg) in a range of from about −60 degreesCelsius to about −110 degrees Celsius. The composition may furthercomprise one or more additional second soft segments, preferablycomprising perfluoropolyether soft segments.

In another embodiment of the disclosure, there is provided a segmentedelastomeric copolymer composition. The composition comprises one or moreα,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolydimethylsiloxane (PDMS) soft segments having an average molecularweight of between about 4000 grams per mole to about 7000 grams permole, wherein the one or more PDMS soft segments is present in an amountof from about 60% by weight to about 85% by weight, based on a totalweight percent of the composition. The composition further comprises oneor more hard segments present in an amount of from about 15% by weightto about 40% by weight, based on the total weight percent of thecomposition, wherein the one or more hard segments comprise acombination of one or more cycloalkyl based diisocyanate species and oneor more low molecular weight diol or diamine chain extenders. Thecomposition preferably has a high flexibility at an environmentaltemperature of down to about −100 degrees Celsius, and further has apercent elongation of greater than about 250%, a high tensile strengthof greater than 25 MPa (megapascals), and a single low glass transitiontemperature (Tg) in a range of from about −60 degrees Celsius to about−110 degrees Celsius.

In another embodiment of the disclosure, there is provided a segmentedelastomeric copolymer composition. The composition comprises one or moreα,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolydimethylsiloxane (PDMS) first soft segments having an averagemolecular weight of between about 4000 grams per mole to about 7000grams per mole. The composition further comprises one or moreperfluoropolyether second soft segments having an average molecularweight of between about 4000 grams per mole to about 7000 grams permole. A total content of the one or more first soft segments and the oneor more second soft segments is present in an amount of from about 60%by weight to about 85% by weight, based on a total weight percent of thecomposition. The composition further comprises one or more hard segmentspresent in an amount of from about 15% by weight to about 40% by weight,based on the total weight percent of the composition. The one or morehard segments comprise a combination of one or more cycloalkyl baseddiisocyanate species and one or more low molecular weight diol ordiamine chain extenders. The composition preferably has a highflexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing a segmented copolymer. The method comprises mixing one ormore α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments having an average molecular weight ofbetween about 2500 grams per mole to about 10,000 grams per mole and oneor more diisocyanate species together to form a first reaction product.The method further comprises mixing the first reaction product and oneor more low molecular weight diol or diamine chain extenders together ina solvent to form a segmented copolymer. The method further comprisesremoving the solvent. The segmented copolymer formed has a highflexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing a segmented copolymer. The method comprises mixing one ormore α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments having an average molecular weight ofbetween about 2500 grams per mole to about 10,000 grams per mole and oneor more diisocyanate species together to form a first reaction product.The method further comprises mixing the first reaction product and oneor more perfluoropolyether second soft segments together to form asecond reaction product. The method further comprises mixing the secondreaction product and one or more low molecular weight diol or diaminechain extenders together in a solvent to form a segmented copolymer. Themethod further comprises removing the solvent. The segmented copolymerformed has a high flexibility at an environmental temperature of down toabout −100 degrees Celsius and further has a percent elongation ofgreater than about 250%, a high tensile strength of greater than about25 MPa (megapascals), and a single low glass transition temperature (Tg)in a range of from about −60 degrees Celsius to about −110 degreesCelsius.

In another embodiment of the disclosure, there is provided a segmentedcopolymer composition. The composition comprises one or more α,ω (alpha,omega) amine or α,ω (alpha, omega) hydroxyl terminated polysiloxanefirst soft segments having an average molecular weight of between about2500 grams per mole to about 10,000 grams per mole. The compositionfurther comprises one or more diisocyanate species. The compositionfurther comprises one or more low molecular weight diol or diamine chainextenders having an average molecular weight of less than 400 grams permole. The composition preferably has a high flexibility at anenvironmental temperature of down to about −100 degrees Celsius, andfurther has a percent elongation of greater than about 250%, a hightensile strength of greater than 25 MPa (megapascals), and a single lowglass transition temperature (Tg) in a range of from about −60 degreesCelsius to about −110 degrees Celsius. The composition may furthercomprise one or more additional second soft segments, preferablycomprising perfluoropolyether soft segments.

In another embodiment of the disclosure, there is provided a segmentedelastomeric copolymer composition. The composition comprises one or moreα,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolydimethylsiloxane (PDMS) soft segments having an average molecularweight of between about 4000 grams per mole to about 7000 grams permole, wherein the one or more PDMS soft segments is present in an amountof from about 60% by weight to about 85% by weight, based on a totalweight percent of the composition. The composition further comprises oneor more hard segments present in an amount of from about 15% by weightto about 40% by weight, based on the total weight percent of thecomposition, wherein the one or more hard segments comprise acombination of one or more cycloalkyl based diisocyanate species, andone or more low molecular weight diol or diamine chain extenders havingan average molecular weight of less than 400 grams per mole. Thecomposition preferably has a high flexibility at an environmentaltemperature of down to about −100 degrees Celsius, and further has apercent elongation of greater than about 250%, a high tensile strengthof greater than 25 MPa (megapascals), and a single low glass transitiontemperature (Tg) in a range of from about −60 degrees Celsius to about−110 degrees Celsius.

In another embodiment of the disclosure, there is provided a segmentedelastomeric copolymer composition. The composition comprises one or moreα,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolydimethylsiloxane (PDMS) first soft segments having an averagemolecular weight of between about 4000 grams per mole to about 7000grams per mole. The composition further comprises one or moreperfluoropolyether second soft segments having an average molecularweight of between about 4000 grams per mole to about 7000 grams permole. A total content of the one or more first soft segments and the oneor more second soft segments is present in an amount of from about 60%by weight to about 85% by weight, based on a total weight percent of thecomposition. The composition further comprises one or more hard segmentspresent in an amount of from about 15% by weight to about 40% by weight,based on the total weight percent of the composition. The one or morehard segments comprise a combination of one or more cycloalkyl baseddiisocyanate species and one or more low molecular weight diol ordiamine chain extenders having an average molecular weight of less than400 grams per mole. The composition preferably has a high flexibility atan environmental temperature of down to about −100 degrees Celsius, andfurther has a percent elongation of greater than about 250%, a hightensile strength of greater than 25 MPa (megapascals), and a single lowglass transition temperature (Tg) in a range of from about −60 degreesCelsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing a segmented copolymer. The method comprises mixing one ormore α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments having an average molecular weight ofbetween about 2500 grams per mole to about 10,000 grams per mole and oneor more diisocyanate species together to form a first reaction product.The method further comprises mixing the first reaction product and oneor more low molecular weight diol or diamine chain extenders having anaverage molecular weight of less than 400 grams per mole, together in asolvent to form a segmented copolymer. The method further comprisesremoving the solvent. The segmented copolymer formed has a highflexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing a segmented copolymer. The method comprises mixing one ormore α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments having an average molecular weight ofbetween about 2500 grams per mole to about 10,000 grams per mole and oneor more diisocyanate species together to form a first reaction product.The method further comprises mixing the first reaction product and oneor more perfluoropolyether second soft segments together to form asecond reaction product. The method further comprises mixing the secondreaction product and one or more low molecular weight diol or diaminechain extenders having an average molecular weight of less than 400grams per mole, together in a solvent to form a segmented copolymer. Themethod further comprises removing the solvent. The segmented copolymerformed has a high flexibility at an environmental temperature of down toabout −100 degrees Celsius and further has a percent elongation ofgreater than about 250%, a high tensile strength of greater than about25 MPa (megapascals), and a single low glass transition temperature (Tg)in a range of from about −60 degrees Celsius to about −110 degreesCelsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing and using a segmented copolymer. The method comprisesmixing one or more α,ω (alpha, omega) amine or α,ω (alpha, omega)hydroxyl terminated polysiloxane first soft segments having an averagemolecular weight of between about 2500 grams per mole to about 10,000grams per mole, and one or more diisocyanate species, together to form afirst reaction product.

The method further comprises mixing the first reaction product, and oneor more low molecular weight diol or diamine chain extenders each havingan average molecular weight of less than 400 grams per mole, together ina solvent to form a segmented copolymer in solution. The solvent is asecondary or tertiary alcohol of isopropanol; tert-butanol; 2-butanol;3-methyl-3-pentanol; 2-methyl-2-pentanol; t-amyl methyl ether; 2,3dimethyl-2-butanol; 3-methyl-1,3-butanediol; 2-3 dimethyl-3-pentanol;3-ethyl-3-pentanol; 2,4-dimethyl-2-pentanol; or 2-methyl-2-hexanol.

The method further comprises applying the segmented copolymer insolution to one or more surfaces via spray coating directly from thesolution with the segmented copolymer. The segmented copolymer formedhas a high flexibility at an environmental temperature of down to about−100 degrees Celsius, and further has a percent elongation of greaterthan about 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing and applying to a surface a segmented copolymer. The methodcomprises mixing one or more α,ω (alpha, omega) amine or α,ω (alpha,omega) hydroxyl terminated polysiloxane first soft segments having anaverage molecular weight of between about 2500 grams per mole to about10,000 grams per mole, and one or more diisocyanate species, together toform a first reaction product.

The method further comprises mixing the first reaction product, and oneor more low molecular weight diol or diamine chain extenders each havingan average molecular weight of less than 400 grams per mole, together ina solvent to form a segmented copolymer in solution. The solvent is asecondary or tertiary alcohol of isopropanol; tert-butanol; 2-butanol;3-methyl-3-pentanol; 2-methyl-2-pentanol; t-amyl methyl ether; 2,3dimethyl-2-butanol; 3-methyl-1,3-butanediol; 2-3 dimethyl-3-pentanol;3-ethyl-3-pentanol; 2,4-dimethyl-2-pentanol; or 2-methyl-2-hexanol. Thesolvent is not removed and the segmented copolymer remains in solutionfor subsequent use.

The method further comprises using the segmented copolymer in solutionby applying the segmented copolymer in solution to the surface via spraycoating directly from the solution with the segmented copolymer. Thesegmented copolymer formed has a high flexibility at an environmentaltemperature of down to about −100 degrees Celsius, and further has apercent elongation of greater than about 250%, a high tensile strengthof greater than about 25 MPa (megapascals), and a single low glasstransition temperature (Tg) in a range of from about −60 degrees Celsiusto about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing and using a segmented copolymer. The method comprisesmixing one or more α,ω (alpha, omega) amine or α,ω (alpha, omega)hydroxyl terminated polysiloxane first soft segments having an averagemolecular weight of between about 2500 grams per mole to about 10,000grams per mole, and one or more diisocyanate species, together to form afirst reaction product.

The method further comprises mixing the first reaction product and oneor more perfluoropolyether second soft segments together to form asecond reaction product. The method further comprises mixing the secondreaction product and one or more low molecular weight diol or diaminechain extenders each having an average molecular weight of less than 400grams per mole, together in a solvent to form a segmented copolymer insolution.

The method further comprises applying the segmented copolymer insolution to one or more surfaces via spray coating directly from thesolution with the segmented copolymer. The segmented copolymer formedhas a high flexibility at an environmental temperature of down to about−100 degrees Celsius, and further has a percent elongation of greaterthan about 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing and using a segmented copolymer. The method comprisesmixing one or more α,ω (alpha, omega) amine or α,ω (alpha, omega)hydroxyl terminated polysiloxane first soft segments having an averagemolecular weight of between about 2500 grams per mole to about 10,000grams per mole, and one or more diisocyanate species, together to form afirst reaction product.

The method further comprises mixing the first reaction product and oneor more second soft segments together to form a second reaction product.The one or more second soft segments is perfluoropolyether; α,ω (alpha,omega) dihydroxy terminated fluoroether; α,ω (alpha, omega) hydroxylterminated poly(perfluoromethylisopropyl ether);polythiodifluoromethylene; polybutadiene; polydioxypropylphosphazene;polydioxyethylphosphazene; polydioxymethylphosphazene; polyisoprene; orpolyisobutylene.

The method further comprises mixing the second reaction product, and oneor more diamine chain extenders each having an average molecular weightof less than 400 grams per mole, together in a solvent to form asegmented copolymer in solution. The one or more diamine chain extendersis isophorone diamine (5-amino-1,3,3-trimethyl cyclohexanemethanamine);bis-(p-aminocyclohexyl)methane; 2,2-bis(4-aminocyclohexyl)propane;4-methyl-1,3-cyclohexane diamine; 2,4-diethyl-6-methylcyclohexane-1,3diamine; or a mixture of two or more thereof.

The method further comprises applying the segmented copolymer insolution to one or more surfaces via spray coating directly from thesolution with the segmented copolymer. The segmented copolymer formedhas a high flexibility at an environmental temperature of down to about−100 degrees Celsius, and further has a percent elongation of greaterthan about 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing and applying to a surface a segmented copolymer. The methodcomprises mixing one or more α,ω (alpha, omega) amine or α,ω (alpha,omega) hydroxyl terminated polysiloxane first soft segments having anaverage molecular weight of between about 2500 grams per mole to about10,000 grams per mole, and one or more diisocyanate species, together toform a first reaction product.

The method further comprises mixing the first reaction product with asolution of one or more second soft segments, wherein the one or moresoft segments is perfluoropolyether; α,ω (alpha, omega) dihydroxyterminated fluoroether; α,ω (alpha, omega) hydroxyl terminatedpoly(perfluoromethylisopropyl ether); polythiodifluoromethylene;polybutadiene; polydioxypropylphosphazene; polydioxyethylphosphazene;polyoxytrimethylene; polydioxymethylphosphazene; polyisoprene; orpolyisobutylene. The method further comprises mixing the first reactionproduct, and one or more low molecular weight diol or diamine chainextenders each having an average molecular weight of less than 400 gramsper mole, together in a solvent to form a segmented copolymer insolution.

The method further comprises applying the segmented copolymer insolution to the surface via spray coating directly from the solutionwith the segmented copolymer. The segmented copolymer formed has a highflexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

The features, functions, and advantages that have been discussed can beachieved independently in various embodiments of the disclosure or maybe combined in yet other embodiments further details of which can beseen with reference to the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure can be better understood with reference to the followingdetailed description taken in conjunction with the accompanying drawingswhich illustrate preferred and exemplary embodiments, but which are notnecessarily drawn to scale, wherein:

FIG. 1A is an illustration of the chemical structure of soft segmentpolydimethysiloxane (PDMS) dihydroxyalkyl terminated used in one or moreembodiments of the segmented copolymer of the disclosure;

FIG. 1B is an illustration of the chemical structure of soft segment α,ωdihydroxy fluoroether used in one or more of the embodiments of thesegmented copolymer of the disclosure;

FIG. 1C is an illustration of the chemical structure of diisocyanate4,4′-methylenebis(cyclohexyl isocyanate) (HMDI) used in one or more ofthe embodiments of the segmented copolymer of the disclosure;

FIG. 1D is an illustration of the chemical structure of chain extender1,2-diaminocyclohexane (DAC) used in one or more of the embodiments ofthe segmented copolymer of the disclosure;

FIGS. 1E-1F are illustrations of the chemical structures of chainextender diethyltoluenediamine (DETDA) used in one or more of theembodiments of the segmented copolymer of the disclosure;

FIG. 2 is a table showing the compositional data of Examples 1-4 of thedisclosure;

FIG. 3 is a table showing the mechanical testing data for Examples 1-4of the disclosure;

FIG. 4 is a table showing solvent compatibility testing parameters;

FIG. 5 is a table showing mass and volume change following fluidexposure for Examples 1-4 of the disclosure;

FIG. 6 is a graph showing modulus versus temperature comparisons betweenone of the embodiments of the segmented copolymer of the disclosure andknown segmented copolymers containing polypropylene oxide (PPO);

FIG. 7 is a graph showing modulus versus temperature comparisons betweensegmented copolymers with differing siloxane block lengths;

FIG. 8 is a graph showing modulus versus temperature dynamic mechanicalanalysis data for Examples 1-4 of the disclosure;

FIG. 9 is an illustration of a flow diagram of an embodiment of a methodof making a segmented copolymer of the disclosure; and,

FIG. 10 is an illustration of a flow diagram of another embodiment of amethod of making a segmented copolymer of the disclosure.

DETAILED DESCRIPTION

Disclosed embodiments will now be described more fully hereinafter withreference to the accompanying drawings, in which some, but not all ofthe disclosed embodiments are shown. Indeed, several differentembodiments may be provided and should not be construed as limited tothe embodiments set forth herein. Rather, these embodiments are providedso that this disclosure will be thorough and complete and will fullyconvey the scope of the disclosure to those skilled in the art.

There are provided embodiments of segmented copolymer composition andmethods of making the compositions. The disclosed embodiments may beused in composite parts for aviation and aerospace aircraft andvehicles, watercraft, rotorcraft, automobiles, trucks, buildingstructures, and other vehicles and craft. Segmented copolymercompositions and methods are disclosed that combine the two propertiesof high mechanical strength with flexibility over a broad temperaturerange. The copolymer compositions show a single low and sharp glasstransition at low temperature (<−100° C.) and an exceptionally broadrubbery plateau or working temperature (ΔT approximately 250° C.).Chemical compositions of siloxane-urethane/urea segmented copolymersthat are able to achieve high tensile strength and elongation valuesusing only PDMS as a soft segment are disclosed. The need to includeadditional soft segments such as polyether based materials to achieveimproved mechanical properties is unnecessary. As a result, thematerials produced are able to display glass transition temperaturescharacteristic of PDMS, broad working temperature ranges, and goodmechanical properties.

Polyurethane elastomers may be one-phase systems or two-phase systems.One-phase systems may be homogeneous chemically crosslinked polymers.Two-phase systems may be block copolymers consisting of a hard phase anda soft phase, joined by covalent linkages. The blocks may be referred toas “segments”. Due to a difference in the structure and chemical natureof the blocks, the blocks may remain as phase separated domains that donot mix. Polyurethane elastomers may be linear segmented copolymersconsisting of one or more soft or flexible segments and one or more hardor rigid segments. As used herein, the term “soft segment” means arelatively flexible (very low hardness or rigidity) component at roomtemperature, having a low density of urethane groups along the polymerbackbone as compared to “hard segments”, and that may be derived fromisocyanates and diols. The soft segments may be obtained by reactingpolyols having molecular weights between 400 grams per mole and 10,000grams per mole. The soft segment provides the polyurethane with a verylow Tg (glass transition temperature). Soft segment concentration istypically the ratio of the mass of polyol chains without terminalhydroxyl groups to the total mass of the polymer, usually expressed as apercentage. The difference, making the total 100%, is hard segmentconcentration. As used herein, the term “hard segment” means arelatively hard and stiff (high hardness) component at room temperature,having a high density of urethane or urea groups along the polymerbackbone as compared to soft segments, and that may be derived fromisocyanates, and short diols or diamines, i.e., chain extenders.Neighboring hard segments may be held together by Van der Waals forcesand hydrogen bonds, forming domains, which act as physical crosslinks.The hard segments provide the polyurethane with a melting point.

As used herein, the term “glass transition temperature (Tg)” means thetemperature above which amorphous regions in an amorphous orsemi-crystalline material produce a transition from a hard and brittleto a molten or rubber-like state but does not melt the crystallineregions. The Tg is lower than the melting temperature (Tm) of thecrystalline state of the material, if one exists. Preferably, thecomposition disclosed herein has a single low glass transitiontemperature (Tg) in a range of from about −60 degrees Celsius to about−110 degrees Celsius.

As used herein, the term “high flexibility” means a high chainflexibility where the glass transition temperature (Tg) is below anapplication temperature range and which allows high deformation, where“application temperature range” means a working temperature range one isinterested in using for a material, such as a material of a componentpart. For example, working temperature ranges may include temperaturesone may expect a material of a component part to experience when thecomponent part is installed in a vehicle, such as an aircraft,automobile, or other structure. For example, an aircraft workingtemperature range may be −100 degrees Celsius to 150 degrees Celsius,and an automobile working temperature range may be −40 degrees Celsiusto 90 degrees Celsius. When the glass transition temperature (Tg) isbelow the application range for a rubber material, it means that suchrubber material will remain flexible when used above the Tg. Preferably,the composition disclosed herein has a high flexibility in anenvironmental temperature of down to about −100 degrees Celsius.

In an embodiment of the disclosure, there is provided a segmentedcopolymer composition. The composition comprises one or more α,ω (alpha,omega) amine or α,ω (alpha, omega) hydroxyl terminated polysiloxanefirst soft segments having an average molecular weight of between about2500 grams per mole to about 10,000 grams per mole. Preferably, the oneor more α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxylterminated polysiloxane first soft segments have an average molecularweight of between about 4000 grams per mole to about 7000 grams permole. More preferably, the one or more α,ω (alpha, omega) amine or α,ω(alpha, omega) hydroxyl terminated polysiloxane first soft segments havean average molecular weight of about 5600 grams per mole. The one ormore α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments is preferably polydimethylsiloxane(PDMS), poly(diphenyl-co-dimethylsiloxane),poly(methyl-3,3,3-trifluoropropylsiloxane),poly(methyl-n-octylsiloxane), poly(di-n-pentylsiloxane),poly(methyl-n-hexylsiloxane), poly(di-n-propylsiloxane),poly(methyl-n-pentylsiloxane), poly(methyl-n-butylsiloxane),poly(di-n-butylsiloxane), poly(methyl-n-propylsiloxane),poly(methylethylsiloxane), poly(methylhydridosiloxane), and/orpolydiethylsiloxane. More preferably, the one or more α,ω (alpha, omega)amine or α,ω (alpha, omega) hydroxyl terminated polysiloxane first softsegments is polydimethylsiloxane (PDMS). FIG. 1A is an illustration of achemical structure 10 of soft segment polydimethysiloxane (PDMS)dihydroxyalkyl terminated used in one or more of the embodiments of thesegmented copolymer of the disclosure. Preferably, the one or morepolysiloxane first soft segments is present in an amount of from about40% by weight to about 95% by weight, based on a total weight percent ofthe composition. More preferably, the one or more polysiloxane firstsoft segments is present in an amount of from about 60% by weight toabout 85% by weight, based on a total weight percent of the composition.Most preferably, the one or more polysiloxane first soft segments ispresent in an amount of about 75% by weight, based on a total weightpercent of the composition.

The composition further comprises one or more diisocyanate species. Theone or more diisocyanate species is preferably4,4′-methylenebis(cyclohexyl isocyanate) (HMDI—Hexamethylenediisocyanate), cycloalkyl based diisocyanates, tolylene-2,4-diisocyante(TDI), 4,4′-methylenebis(phenyl isocyanate) (MDI), and/or isophoronediisocyanate (IDI). More preferably, the one or more diisocyanatespecies is 4,4′-methylenebis(cyclohexyl isocyanate) (HMDI—Hexamethylenediisocyanate). FIG. 1C is an illustration of a chemical structure 14 ofdiisocyanate 4,4′-methylenebis(cyclohexyl isocyanate)(HMDI—Hexamethylene diisocyanate) used in one or more of the embodimentsof the segmented copolymer of the disclosure.

The composition further comprises one or more low molecular weight diolor diamine chain extenders, where “low molecular weight” means the diolchain extender or the diamine chain extender each preferably having anaverage molecular weight of less than 400 grams per mole (g/mol); andmore preferably, each having an average molecular weight of betweenabout 50 grams per mole and about 399 grams per mole; and mostpreferably, each having an average molecular weight of between about 100grams per mole and about 250 grams per mole. The one or more lowmolecular weight diol or diamine chain extenders is/are preferably lowmolecular weight linear diamines, cycloalkyl diamines, cycloaliphaticdiamines, aromatic diamines, 1,2-diaminocyclohexane (DAC),1,3-diaminocyclohexane, 1,4-diaminocyclohexane, diethyltoluenediamine(DETDA), isophorone diamine (5-amino-1,3,3-trimethylcyclohexanemethanamine), bis-(p-aminocyclohexyl)methane,2,2-bis(4-aminocyclohexyl)propane, 4-methyl-1,3-cyclohexane diamine,2,4-diethyl-6-methylcyclohexane-1,3 diamine, and/or a mixture of two ormore thereof. According to the CAS (Chemical Abstracts Service)registry, the molecular weights in grams per mole for the following lowmolecular weight chain extenders include: 1,2-diaminocyclohexane (DAC)has a molecular weight of 114.19 g/mol; 1,3-diaminocyclohexane has amolecular weight of 114.19 g/mol; 1,4-diaminocyclohexane has a molecularweight of 114.19 g/mol; diethyltoluenediamine (DETDA) has a molecularweight of 178.28 g/mol; isophorone diamine (5-amino-1,3,3-trimethylcyclohexanemethanamine) has a molecular weight of 170.25 g/mol;bis-(p-aminocyclohexyl)methane has a molecular weight of 210.37 g/mol;2,2-bis(4-aminocyclohexyl)propane has a molecular weight of 238.42g/mol; 4-methyl-1,3-cyclohexane diamine has a molecular weight of 128.25g/mol; and 2,4-diethyl-6-methylcyclohexane-1,3 diamine has a molecularweight of 179 g/mol. More preferably, the one or more low molecularweight diol or diamine chain extenders is 1,2-diaminocyclohexane (DAC)or 1,2-diaminocyclohexane (DAC) plus diethyltoluenediamine (DETDA), suchas ETHACURE 100 obtained from Albermarle Corporation of Baton Rouge, La.(ETHACURE is a registered trademark of Albermarle Corporation of BatonRouge, La.). FIG. 1D is an illustration of the chemical structure ofchain extender 1,2-diaminocyclohexane (DAC) used in one or more of theembodiments of the segmented copolymer of the disclosure. FIG. 1E andFIG. 1F are illustrations of chemical structures 18, 20 of chainextender diethyltoluenediamine (DETDA) (ETHACURE 100) used in one ormore of the embodiments of the segmented copolymer of the disclosure.The components are added at a ratio such that the equivalents ofisocyanate species are stoichiometrically equal to the total alcohol andamine species in the composition. Preferably, one or more hard segmentscomprised of a combination of one or more diisocyanate species and oneor more low molecular weight diol or diamine chain extenders,(preferably, the one or more low molecular weight diol or diamine chainextenders each have an average molecular weight of less than 400 gramsper mole, and more preferably, each have an average molecular weight ofbetween about 50 grams per mole and about 399 grams per mole, and mostpreferably, each have an average molecular weight of between about 100grams per mole and about 250 grams per mole), is present in an amount offrom about 5% by weight to about 60% by weight, based on a total weightpercent of the composition. More preferably, the one or more hardsegments comprised of a combination of one or more diisocyanate speciesand one or more low molecular weight diol or diamine chain extenders, ispresent in an amount of from about 15% by weight to about 40% by weight,based on a total weight percent of the composition. Most preferably, theone or more hard segments comprised of a combination of one or morediisocyanate species and one or more low molecular weight diol ordiamine chain extenders is present in an amount of about 25% by weight,based on a total weight percent of the composition. The chain extenderis preferably composed of a mixture of low molecular weight cycloalkyldiamines and aromatic diamines. This serves to reduce the reaction rateand increase of the molecular weight of the system over time leading toa slower build in viscosity of the system.

The combination of HMDI as diisocyanate and cyclohexyl groups such asdiaminocyclohexane combine two chemical species that share the commoncyclohexyl structure. Such a hard segment has a very high density ofcycloalkyl groups which may be more compatible with the PDMS softsegment than similar aromatic or alkyl chain extenders. This can reducephase separation at the interface between soft and hard segmentscreating more of a gradient interface rather than a sharp transition andallowing greater stresses in the material to display greater tensilestrength and elongation.

Another disclosed embodiment is the use of siloxane based diamine ordiol curatives or chain extenders to complete the hard segments. Thiscan reduce the solubility parameter contrast between hard and softsegments to an even greater extent by matching the chemical structure ofthe soft segment more precisely.

In another embodiment, the composition may further comprise one or moresecond soft segments. The one or more second soft segments is preferablyperfluoropolyether, α,ω (alpha, omega) dihydroxy terminated fluoroether,α,ω (alpha, omega) hydroxyl terminated poly(perfluoromethylisopropylether), polythiodifluoromethylene, polybutadiene,polydioxypropylphosphazene, polydioxyethylphosphazene,polyoxytrimethylene, polydioxymethylphosphazene, polyisoprene, and/orpolyisobutylene. More preferably, the one or more second soft segmentsis aminocyclohexyl)methane hydroxyl terminatedpoly(perfluoromethylisopropyl ether). FIG. 1B is an illustration of achemical structure 12 of a soft segment α,ω (alpha, omega) dihydroxyfluoroether FOMBLIN ZDol 4000 obtained from Solvay Solexis, Inc. ofThorofare, N.J. (FOMBLIN is a registered trademark of Solvay Solexis,Inc. of Thorofare, N.J.) that may be used in one or more of theembodiments of the segmented copolymer of the disclosure. FOMBLIN ZDol4000 is a dihydroxy derivative of perfluoropolyxoyalkane and has amolecular weight of 3900-4100. Preferably, the one or more second softsegments or soft segment components have an average molecular weight ofbetween about 2500 grams per mole to about 10,000 grams per mole. Morepreferably, the one or more second soft segments or soft segmentcomponents have an average molecular weight of between about 4000 gramsper mole to about 7000 grams per mole. Most preferably, the one or moresecond soft segments or soft segment components have an averagemolecular weight of between about 4000 grams per mole. Preferably, theone or more second soft segments is present in an amount of from about5% by weight to about 50% by weight, based on a total weight percent ofthe soft segment content. More preferably, the one or more second softsegments is present in an amount of from about 20% by weight to about50% by weight, based on a total weight percent of the soft segmentcontent. Most preferably, the one or more second soft segments ispresent in an amount of about 40% by weight, based on a total weightpercent of the soft segment content.

Thus, in one embodiment the soft segment may consist of a first softsegment such as polydimethylsiloxane (PDMS) and a second soft segmentsuch as a dihydroxy terminated fluoroether or perfluoropolyether. Theperfluoropolyether materials also have exceptionally low glasstransition temperatures similar to polydimethylsiloxane (PDMS) in orderto maintain an overall low Tg for the copolymer material. Preferably,the one or more soft segments have a single low glass transitiontemperature (Tg) in a range of from about −60 degrees Celsius to about−110 degrees Celsius. More preferably, polydimethylsiloxane (PDMS) has aglass transition temperature (Tg) of −110 degrees Celsius, andperfluoropolyether has a glass transition temperature (Tg) of −100degrees Celsius. While the perfluoropolyether soft segment may be addedto the solution sequentially following growth of the siloxane softsegments, its function serves to improve chemical resistance of thematerial. The function of the second soft segment such as theperfluoropolyether soft segment is not intended to serve as aninterfacial barrier between the polydimethylsiloxane (PDMS) softsegments and the urea hard segments. This is due to the fact thatpolyfluorocarbons possess the same low solubility parameters aspolysiloxanes of approximately 12-17 (J/cm³)^(1/2) (Joules per cubiccentimeter) which is in strong contrast to that of polyurea segmentswith a solubility parameter of 45 (J/cm³)^(1/2). The low solubilityparameter of the polyfluoroether segments differs from that of a secondsoft segment such as poly(propylene oxide) which has an intermediatesolubility parameter of 23.5 (J/cm³)^(1/2) helping to create a gradientinterface with respect to solubility parameters of the blocks.

The compositions of the disclosed embodiments preferably have a highflexibility at an environmental temperature of down to about −100degrees Celsius. Preferably, the compositions of the disclosedembodiments further have a percent elongation of greater than about250%, a high tensile strength of greater than 25 MPa (megapascals), anda single low glass transition temperature (Tg) in a range of from about−60 degrees Celsius to about −110 degrees Celsius. Preferably, thecompositions of the disclosed embodiments have a temperature insensitivemodulus between a range of from about −100 degrees Celsius to about 150degrees Celsius.

In another embodiment of the disclosure, there is provided a segmentedelastomeric copolymer composition. The composition comprises one or moreα,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolydimethylsiloxane (PDMS) soft segments having an average molecularweight of between about 4000 grams per mole to about 7000 grams permole, wherein the one or more PDMS soft segments is present in an amountof from about 60% by weight to about 85% by weight, based on a totalweight percent of the composition. The composition further comprises oneor more hard segments present in an amount of from about 15% by weightto about 40% by weight, based on the total weight percent of thecomposition, wherein the one or more hard segments comprise acombination one or more cycloalkyl based diisocyanate species and one ormore low molecular weight diol or diamine chain extenders. Preferably,the one or more low molecular weight diol or diamine chain extenderseach have an average molecular weight of less than 400 grams per mole,and more preferably, each have an average molecular weight of betweenabout 50 grams per mole and about 399 grams per mole, and mostpreferably, each have an average molecular weight of between about 100grams per mole and about 250 grams per mole. The components are added ata ratio such that the equivalents of diisocyanate species arestoichiometrically equal to the total alcohol and amine species in thecomposition. The composition preferably has a high flexibility at anenvironmental temperature of down to about −100 degrees Celsius, andfurther has a percent elongation of greater than about 250%, a hightensile strength of greater than 25 MPa (megapascals), and a single lowglass transition temperature (Tg) in a range of from about −60 degreesCelsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a segmentedelastomeric copolymer composition. The composition comprises one or moreα,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolydimethylsiloxane (PDMS) first soft segments having an averagemolecular weight of between about 4000 grams per mole to about 7000grams per mole. The composition further comprises one or moreperfluoropolyether second soft segments having an average molecularweight of between about 4000 grams per mole to about 7000 grams permole. A total content of the one or more first soft segments and the oneor more second soft segments is present in an amount of from about 60%by weight to about 85% by weight, based on a total weight percent of thecomposition. The composition further comprises one or more hard segmentspresent in an amount of from about 15% by weight to about 40% by weight,based on the total weight percent of the composition. The one or morehard segments comprise a combination of one or more cycloalkyl baseddiisocyanate species and one or more low molecular weight diol ordiamine chain extenders. Preferably, the one or more low molecularweight diol or diamine chain extenders each have an average molecularweight of less than 400 grams per mole, and more preferably, each havean average molecular weight of between about 50 grams per mole and about399 grams per mole, and most preferably, each have an average molecularweight of between about 100 grams per mole and about 250 grams per mole.The components are added at a ratio such that the equivalents ofdiisocyanate species are stoichiometrically equal to the total alcoholand amine species in the composition. The composition preferably has ahigh flexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.

In another embodiment of the disclosure, there is provided a method ofsynthesizing a segmented copolymer. FIG. 9 is an illustration of a flowdiagram of an embodiment of a method 50 of making one of the embodimentsof the segmented copolymers of the disclosure. The method 50 comprisesstep 52 of mixing one or more α,ω (alpha, omega) amine or α,ω (alpha,omega) hydroxyl terminated polysiloxane first soft segments preferablyhaving an average molecular weight of between about 2500 grams per moleto about 10,000 grams per mole and one or more diisocyanate speciestogether to form a first reaction product. More preferably, the one ormore α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments have an average molecular weight ofbetween about 4000 grams per mole to about 7000 grams per mole. Mostpreferably, the one or more α,ω (alpha, omega) amine or α,ω (alpha,omega) hydroxyl terminated polysiloxane first soft segments have anaverage molecular weight of about 5600 grams per mole. The one or moreα,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments is preferably polydimethylsiloxane(PDMS), poly(diphenyl-co-dimethylsiloxane),poly(methyl-3,3,3-trifluoropropylsiloxane),poly(methyl-n-octylsiloxane), poly(di-n-pentylsiloxane),poly(methyl-n-hexylsiloxane), poly(di-n-propylsiloxane),poly(methyl-n-pentylsiloxane), poly(methyl-n-butylsiloxane),poly(di-n-butylsiloxane), poly(methyl-n-propylsiloxane),poly(methylethylsiloxane), poly(methylhydridosiloxane), and/orpolydiethylsiloxane. More preferably, the one or more α,ω (alpha, omega)amine or α,ω (alpha, omega) hydroxyl terminated polysiloxane first softsegments is polydimethylsiloxane (PDMS). Preferably, the one or morepolysiloxane first soft segments is present in an amount of from about40% by weight to about 95% by weight, based on a total weight percent ofthe composition. More preferably, the one or more polysiloxane firstsoft segments is present in an amount of from about 60% by weight toabout 85% by weight, based on a total weight percent of the composition.Most preferably, the one or more polysiloxane first soft segments ispresent in an amount of about 75% by weight, based on a total weightpercent of the composition.

The one or more diisocyanate species is preferably4,4′-methylenebis(cyclohexyl isocyanate) (HMDI), cycloalkyl baseddiisocyanates, tolylene-2,4-diisocyante (TDI), 4,4′-methylenebis(phenylisocyanate) (MDI), and/or isophorone diisocyanate (IDI). Morepreferably, the one or more diisocyanate species is4,4′-methylenebis(cyclohexyl isocyanate) (HMDI).

The method further comprises step 54 of mixing the first reactionproduct and one or more low molecular weight diol or diamine chainextenders together in a solvent to form a segmented copolymer. The oneor more low molecular weight diol or diamine chain extenders preferablyeach have an average molecular weight of less than 400 grams per mole,and more preferably, each have an average molecular weight of betweenabout 50 grams per mole and about 399 grams per mole, and mostpreferably, each have an average molecular weight of between about 100grams per mole and about 250 grams per mole. The one or more lowmolecular weight diol or diamine chain extenders is preferably lowmolecular weight linear diamines, cycloalkyl diamines, cycloaliphaticdiamines, aromatic diamines, 1,2-diaminocyclohexane (DAC),1,3-diaminocyclohexane, 1,4-diaminocyclohexane, diethyltoluenediamine(DETDA) (ETHACURE 100), isophorone diamine (5-amino-1,3,3-trimethylcyclohexanemethanamine), bis-(p-aminocyclohexyl)methane,2,2-bis(4-aminocyclohexyl)propane, 4-methyl-1,3-cyclohexane diamine,2,4-diethyl-6-methylcyclohexane-1,3 diamine, or a mixture of two or morethereof. More preferably, the one or more low molecular weight diol ordiamine chain extenders is 1,2-diaminocyclohexane (DAC). The componentsare added at a ratio such that the equivalents of diisocyanate speciesare stoichiometrically equal to the total alcohol and amine species inthe composition. Preferably, one or more hard segments comprised of acombination of one or more diisocyanate species and one or more lowmolecular weight diol or diamine chain extenders, (preferably, the oneor more low molecular weight diol or diamine chain extenders each havean average molecular weight of less than 400 grams per mole, and morepreferably, each have an average molecular weight of between about 50grams per mole and about 399 grams per mole, and most preferably, eachhave an average molecular weight of between about 100 grams per mole andabout 250 grams per mole), is present in an amount of from about 5% byweight to about 60% by weight, based on a total weight percent of thecomposition. More preferably, the one or more hard segments comprised ofa combination of one or more diisocyanate species and one or more lowmolecular weight diol or diamine chain extenders is present in an amountof from about 15% by weight to about 40% by weight, based on a totalweight percent of the composition. Most preferably, the one or more hardsegments comprised of a combination of one or more diisocyanate speciesand one or more low molecular weight diol or diamine chain extenders ispresent in an amount of about 25% by weight, based on a total weightpercent of the composition.

Preferably, the solvent is a secondary or tertiary alcohol comprised ofisopropanol, tert-butanol, 2-butanol, 3-methyl-3-pentanol,2-methyl-2-pentanol, t-amyl methyl ether, 2,3 dimethyl-2-butanol,3-methyl-1,3-butanediol, 2-3 dimethyl-3-pentanol, 3-ethyl-3-pentanol,2,4-dimethyl-2-pentanol, 2-methyl-2-hexanol, or another suitablesecondary or tertiary alcohol. More preferably, the solvent isisopropanol. Preferably, the segmented copolymer formed has a highflexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.Preferably, the segmented copolymer has a temperature insensitivemodulus between a range of from about −100 degrees Celsius to about 150degrees Celsius.

The method may further comprise step 56 of removing the solvent. In oneembodiment of the method, the solvent is not removed and the segmentedcopolymer remains in solution for subsequent use. This can be applied toa surface at a later time convenient for a user. In an exemplaryembodiment, the segmented copolymer may be applied to surfaces via spraycoating directly from solution. In another embodiment of the method, thefirst reaction product and the mixture of chain extenders are preparedseparately and are able to be stored long term prior to the addition ofa solvent and combination to form the final product.

In another embodiment of the disclosure, there is provided a method ofsynthesizing a segmented copolymer. FIG. 10 is an illustration of a flowdiagram of another embodiment of a method 80 of making another one ofthe embodiments of the segmented copolymers of the disclosure. Themethod comprises step 82 of mixing one or more α,ω (alpha, omega) amineor α,ω (alpha, omega) hydroxyl terminated polysiloxane first softsegments preferably having an average molecular weight of between about2500 grams per mole to about 10,000 grams per mole and one or morediisocyanate species together to form a first reaction product. Morepreferably, the one or more α,ω (alpha, omega) amine or α,ω (alpha,omega) hydroxyl terminated polysiloxane first soft segments have anaverage molecular weight of between about 4000 grams per mole to about7000 grams per mole. Most preferably, the one or more α,ω (alpha, omega)amine or α,ω (alpha, omega) hydroxyl terminated polysiloxane first softsegments have an average molecular weight of between about 5600 gramsper mole. The one or more α,ω (alpha, omega) amine or α,ω (alpha, omega)hydroxyl terminated polysiloxane first soft segments is preferablypolydimethylsiloxane, poly(diphenyl-co-dimethylsiloxane),poly(methyl-3,3,3-trifluoropropylsiloxane),poly(methyl-n-octylsiloxane), poly(di-n-pentylsiloxane),poly(methyl-n-hexylsiloxane), poly(di-n-propylsiloxane),poly(methyl-n-pentylsiloxane), poly(methyl-n-butylsiloxane),poly(di-n-butylsiloxane), poly(methyl-n-propylsiloxane),poly(methylethylsiloxane), poly(methylhydridosiloxane), orpolydiethylsiloxane. More preferably, the one or more α,ω (alpha, omega)amine or α,ω (alpha, omega) hydroxyl terminated polysiloxane first softsegments is polydimethylsiloxane. Preferably, the one or morepolysiloxane first soft segments is present in an amount of from about40% by weight to about 95% by weight, based on a total weight percent ofthe composition. More preferably, the one or more polysiloxane firstsoft segments is present in an amount of from about 60% by weight toabout 85% by weight, based on a total weight percent of the composition.Most preferably, the one or more polysiloxane first soft segments ispresent in an amount of about 75% by weight, based on a total weightpercent of the composition.

The one or more diisocyanate species is preferably4,4′-methylenebis(cyclohexyl isocyanate) (HMDI), cycloalkyl baseddiisocyanates, tolylene-2,4-diisocyante (TDI), 4,4′-methylenebis(phenylisocyanate) (MDI), or isophorone diisocyanate (IDI). More preferably,the one or more diisocyanate species consists of4,4′-methylenebis(cyclohexyl isocyanate) (HMDI).

The method further comprises step 84 of mixing the first reactionproduct and one or more perfluoropolyether second soft segments togetherto form a second reaction product. Preferably, the one or moreperfluoropolyether second soft segments is α,ω (alpha, omega) dihydroxyterminated fluoroether, or α,ω (alpha, omega) hydroxyl terminatedpoly(perfluoromethylisopropyl ether). More preferably, the one or moreperfluoropolyether second soft segments is α,ω hydroxyl terminatedpoly(perfluoromethylisopropyl ether). Preferably, the one or moreperfluoropolyether second soft segments have an average molecular weightof between about 2500 grams per mole to about 10,000 grams per mole.More preferably, the one or more perfluoropolyether second soft segmentshave an average molecular weight of between about 4000 grams per mole toabout 7000 grams per mole. Most preferably, the one or moreperfluoropolyether second soft segments have an average molecular weightof between about 4000 grams per mole. Preferably, the one or moreperfluoropolyether second soft segments is present in an amount of fromabout 5% by weight to about 50% by weight, based on a total weightpercent of the soft segment content. More preferably, the one or moreperfluoropolyether second soft segments is present in an amount of fromabout 20% by weight to about 50% by weight, based on a total weightpercent of the soft segment content. Most preferably, the one or moreperfluoropolyether second soft segments is present in an amount of about40% by weight, based on a total weight percent of the soft segmentcontent.

The method further comprises step 86 of mixing the second reactionproduct and one or more low molecular weight diol or diamine chainextenders together in a solvent to form a segmented copolymer. The oneor more low molecular weight diol or diamine chain extenders preferablyeach have an average molecular weight of less than 400 grams per mole,and more preferably, each have an average molecular weight of betweenabout 50 grams per mole and about 399 grams per mole, and mostpreferably, each have an average molecular weight of between about 100grams per mole and about 250 grams per mole. The one or more lowmolecular weight diol or diamine chain extenders is preferably lineardiamines, cycloalkyl diamines, cycloaliphatic diamines, aromaticdiamines, 1,2-diaminocyclohexane (DAC), 1,3-diaminocyclohexane,1,4-diaminocyclohexane, diethyltoluenediamine (DETDA) (ETHACURE 100),isophorone diamine (5-amino-1,3,3-trimethyl cyclohexanemethanamine),bis-(p-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane,4-methyl-1,3-cyclohexane diamine, 2,4-diethyl-6-methylcyclohexane-1,3diamine, or a mixture of two or more thereof. More preferably, the oneor more low molecular weight diol or diamine chain extenders consist of1,2-diaminocyclohexane (DAC). The components are added at a ratio suchthat the equivalents of diisocyanate species are stoichiometricallyequal to the total alcohol and amine species in the composition.Preferably, one or more hard segments comprised of a combination of oneor more diisocyanate species and one or more low molecular weight diolor diamine chain extenders, (preferably each have an average molecularweight of less than 400 grams per mole, and more preferably, each havean average molecular weight of between about 50 grams per mole and about399 grams per mole, and most preferably, each have an average molecularweight of between about 100 grams per mole and about 250 grams permole), is present in an amount of from about 5% by weight to about 60%by weight, based on a total weight percent of the composition. Morepreferably, the one or more hard segments comprised of a combination ofone or more diisocyanate species and one or more low molecular weightdiol or diamine chain extenders is present in an amount of from about15% by weight to about 40% by weight, based on a total weight percent ofthe composition. Most preferably, the one or more hard segmentscomprised of a combination of one or more diisocyanate species and oneor more low molecular weight diol or diamine chain is present in anamount of about 25% by weight, based on a total weight percent of thecomposition.

Preferably, the solvent is a secondary or tertiary alcohol ofisopropanol, tert-butanol, 2-butanol, 3-methyl-3-pentanol,2-methyl-2-pentanol, t-amyl methyl ether, 2,3 dimethyl-2-butanol,3-methyl-1,3-butanediol, 2-3 dimethyl-3-pentanol, 3-ethyl-3-pentanol,2,4-dimethyl-2-pentanol, 2-methyl-2-hexanol, or another suitablesecondary or tertiary alcohol. More preferably, the solvent isisopropanol. Preferably, the segmented copolymer formed has a highflexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.Preferably, the segmented copolymer has a temperature insensitivemodulus between a range of from about −100 degrees Celsius to about 150degrees Celsius.

The method may further comprise step 88 of removing the solvent. In oneembodiment of the method, the solvent is not removed and the segmentedcopolymer remains in solution for subsequent use. This can be applied toa surface at a later time convenient for a user. In an exemplaryembodiment, the segmented copolymer may be applied to surfaces via spraycoating directly from solution. In another embodiment of the method, thefirst reaction product and the mixture of chain extenders are preparedseparately and are able to be stored long term prior to the addition ofa solvent and combination to form the final product.

EXAMPLES

Various embodiments of the segmented copolymer compositions discussedabove were prepared and various mechanical tests were performed.Compositions were prepared for Examples 1-6. FIG. 2 is a table showingthe compositional data of Examples 1-4. FIG. 3 is a table showing themechanical testing data for Examples 1-4. Experiments were conducted(Examples 5 and 6) with and without additional intermediate polyethersegments in order to demonstrate the need to remove polyether segmentsto achieve low temperature (<50° C.) flexibility.

Materials and Methods. To prepare the sample compositions, the followingmaterials were obtained: (1) α,ω bishydroxyl terminatedpolydimethylsiloxane (PDMS) soft segment having an average molecularweight (Mn) of 5600 g/mol (grams per mole) was obtained fromSigma-Aldrich of St. Louis, Mo.; (2) 4,4′-methylenebis(cyclohexylisocyanate) (HMDI) obtained from Sigma-Aldrich of St. Louis, Mo.; (3)1,2-diaminocyclohexane (DAC) was obtained from Sigma-Aldrich of St.Louis, Mo.; (4) ETHACURE 100 was obtained from Albermarle Corporation ofBaton Rouge, La.; (5) FOMBLIN Zdol 4000 fluoroether soft segment havingan average molecular weight (Mn) of 4000 g/mol was obtained from SolvaySolexis, Inc. of Thorofare, N.J.; and (6) isopropanol solvent wasobtained from Mallinckrodt Baker of Phillipsburg, N.J., and theisopropanol was dried over activated 4 Å (Angstrom) molecular sieves. Inaddition, triethylamine was obtained from Sigma-Aldrich of St. Louis,Mo.; was dried over CaH₂ (calcium hydride) also obtained fromSigma-Aldrich of St. Louis, Mo., and was distilled; and JeffamineD-2000, an α,ω diamino poly(propylene oxide) having an average molecularweight (Mn) was obtained from Huntsman of Woodland, Tex.

Tensile testing was performed on an INSTRON 5565 tensile testing machineobtained from Instron of Canton, Mass. (INSTRON is a registeredtrademark owned by Illinois Tool Works Inc. of Glenview, Ill.,) using acrosshead speed of 2.5 mm/min (millimeters per minute). Dynamicmechanical analysis was performed on a DMA Q800 dynamic mechanicalanalysis machine obtained from TA Instruments of New Castle, Del. Scanswere run at a frequency of 1 Hz (Hertz) with a temperature ramp rate of3° C./min (degrees Celsius per minute).

Films were cast from shallow PTFE (polytetrafluoroethylene) molds ofeither 2 inches by 2 inches or 3 inches by 3 inches in area. Viscouspolymer solution was poured into the shallow tray and covered to allowthe film to flow and achieve a uniform thickness for mechanical testingsamples. The cover was then removed and the solvent allowed toevaporate. Films were then placed in a vacuum chamber to ensure removalof residual solvent.

Example 1

In Example 1, PDMS (5.0 g (grams), 0.893 mmoles (millimoles)) and HMDI(1.17 g, 4.46 mmoles) were charged to a vial and stirred with heating at90° C. until the mixture turned clear (typically 1-2 (one to two) hours)and then was heated for 3 (three) hours more at 90° C. The mixture wasthen cooled to ambient temperature. Isopropanol (8 g) was added to themixture and stirred until the mixture was homogeneous. In a separatevial, DAC was measured (407 mg (milligrams), 3.57 mmoles) and dissolvedin isopropanol (2 g). These two solutions were combined and vigorouslymixed. After approximately 5 (five) minutes, the solution was pouredinto a 3 inch by 3 inch PTFE mold and covered overnight. The isopropanolwas then removed through evaporation to produce a film (approximately0.5 mm (millimeters) thick) for use in mechanical testing.

Example 2

In Example 2, PDMS (5.0 g, 0.893 mmoles) and HMDI (1.17 g, 4.46 mmoles)were charged to a vial and stirred with heating at 90° C. until themixture turned clear (typically 1-2 (one to two) hours) and then washeated for 3 (three) hours more at 90° C. The mixture was then cooled toambient temperature. Isopropanol (6 g) was added to the mixture andstirred until the mixture was homogeneous. In a separate vial, DAC (305mg, 2.68 mmoles) and ETHACURE 100 (159 mg, 0.893 mmoles) were dissolvedin isopropanol (2 g). These two solutions were combined and vigorouslymixed. After approximately 5 (five) minutes, the solution was pouredinto a 3 inch by 3 inch PTFE mold and covered overnight. The isopropanolwas then removed through evaporation to produce a film (approximately0.5 mm thick) for use in mechanical testing.

Example 3

In Example 3, PDMS (3.5 g, 0.625 mmoles) and HMDI (1.36 g, 5.2 mmoles)were charged to a vial and stirred. An aliquot of triethylamine(approximately 10 uL (microliters)) was added via capillary tube and thesolution was stirred with heating at 90° C. for 3 (three) hours. α,ωdihydroxy fluoroether (FOMBLIN ZDol 4000) was then added (1.67 g, 0.417mmoles) and the mixture stirred for 3 (three) more hours at 90° C. Themixture had a turbid appearance upon addition of the fluoroether. Themixture was then cooled to ambient temperature. Isopropanol (8 g) wasadded to the mixture and stirred until the mixture was homogeneous. In aseparate vial, DAC was measured (474 mg, 4.16 mmoles) and dissolved inisopropanol (2 g). These two solutions were combined and vigorouslymixed. After approximately 5 (five) minutes, the solution was pouredinto a 3 inch by 3 inch PTFE mold and covered overnight. The isopropanolwas then removed through evaporation to produce a film (approximately0.5 mm thick) for use in mechanical testing.

Example 4

In Example 4, PDMS (3.5 g, 0.625 mmoles) and HMDI (1.36 g, 5.2 mmoles)were charged to a vial and stirred. An aliquot of triethylamine(approximately 10 uL) was added via capillary tube and the solution wasstirred with heating at 90° C. for 3 (three) hours. α,ω dihydroxyfluoroether (FOMBLIN ZDol 4000) was then added (1.67 g, 0.417 mmoles)and the mixture stirred for 3 (three) more hours at 90° C. The mixturewas then cooled to ambient temperature. Isopropanol (6 g) was added tothe mixture and stirred until the mixture was homogeneous. In a separatevial, DAC (356 mg, 3.12 mmoles) and ETHACURE 100 (185 mg, 1.04 mmoles)were dissolved in isopropanol (2 g). These two solutions were combinedand vigorously mixed. After approximately 5 (five) minutes, the solutionwas poured into a 3 inch by 3 inch PTFE mold and covered overnight. Theisopropanol was then removed through evaporation to produce a film(approximately 0.5 mm thick) for use in mechanical testing.

Example 5

In Example 5, PDMS (3.5 g, 0.625 mmoles) and HMDI (819 mg, 3.13 mmoles)were charged to a vial and stirred. An aliquot of triethylamine(approximately 10 uL) was added via capillary tube and the solution wasstirred with heating at 90° C. until the mixture turned clear (typically1 to 2 hours) and then for 3 (three) hours more at 90° C. The mixturewas then cooled to ambient temperature. Isopropanol (6 g) was added tothe mixture and stirred until the mixture was homogeneous. α,ω diaminopolypropylene oxide (Jeffamine D-2000) was then added (1.25 g, 0.625mmoles) dropwise to the solution while stirring vigorously and themixture left to stand for 30 (thirty) minutes at room temperature. In aseparate vial, DAC (214 mg, 1.88 mmoles) was dissolved in isopropanol (2g). These two solutions were combined and vigorously mixed. The solutionwas promptly poured into a 3 inch by 3 inch PTFE mold and coveredovernight. The isopropanol was then removed through evaporation toproduce a film (approximately 0.5 mm thick) for use in mechanicaltesting.

Example 6

In Example 6, PDMS (3.5 g, 0.625 mmoles) and HMDI (1.31 g, 5.0 mmoles)were charged to a vial and stirred. An aliquot of triethylamine(approximately 10 uL) was added via capillary tube and the solution wasstirred with heating at 90° C. until the mixture turned clear (typically1 to 2 hours) and then for 3 (three) hours more at 90° C. The mixturewas then cooled to ambient temperature. Isopropanol (6 g) was added tothe mixture and stirred until the mixture was homogeneous. α,ω diaminopolypropylene oxide (Jeffamine D-2000) was then added (2.50 g, 1.25mmoles) dropwise to the solution while stirring vigorously and themixture left to stand for 30 (thirty) minutes at room temperature. In aseparate vial, DAC (355 mg, 3.12 mmoles) was dissolved in isopropanol (2g). These two solutions were combined and vigorously mixed. The solutionwas promptly poured into a 3 inch by 3 inch PTFE mold and coveredovernight. The isopropanol was then removed through evaporation toproduce a film (approximately 0.5 mm thick) for use in mechanicaltesting.

Solvent compatibility testing was performed by submerging test strips ofmaterial into fluids over a fixed time and temperature. Test materialswere approximately 30 mm (millimeters) in length by 6 mm (millimeters)in width by 0.5 mm (millimeters) in height. Each strip was measured forboth the initial dimension and mass before exposure to fluid. FIG. 4 isa table showing solvent compatibility testing parameters. The table inFIG. 4 describes the fluids used, including (1) JP8 (Jet Propellant 8)jet fuel; (2) engine oil such as MOBIL Jet Oil II from Exxon MobilCorporation of Irving, Tex. (MOBIL is a registered trademark of ExxonMobil Corporation of Irving, Tex.); (3) hydraulic fluid such as CASTROLBRAYCO Micronic 882 obtained from Air BP Lubricants of Parsippany, N.J.(CASTROL and BRAYCO are registered trademarks of Castrol IndustrialNorth America of Warrenville, Ill.), and (4) deionized water. Theexposure time for the JP8 jet fuel was 7 (seven) days and the exposuretemperature was ambient. The exposure time for the engine oil was 24(twenty-four) hours and the exposure temperature was 120° C. Theexposure time for the hydraulic fluid was 7 (seven) days and theexposure temperature was ambient. The exposure time for the deionizedwater was 7 (seven) days and the exposure temperature was 49° C.Following exposure, the test strips were removed from the fluid, blotteddry of any excess liquid on the surface, and both dimensions and masswere measured. The changes following exposure were recorded. FIG. 5 is atable showing the percent mass change and the percent volume changefollowing fluid exposure for Examples 1-4.

It has been unexpectedly discovered that the combination of HMDI asisocyanate and cylcohexyl moieties (e.g., diaminocyclohexane) as chainextenders in a siloxane-urethane/urea segmented copolymer systemproduces elastomeric materials that maintain flexibility at lowtemperatures while demonstrating superior mechanical properties.Elastomeric materials with low glass transition temperatures (less thanor equal to (≦) −100° C.) and good mechanical properties have beendeveloped and demonstrated. These are composed of siloxane-urethane/ureacopolymers synthesized using segmented techniques. The disclosedmaterials possess high tensile strength (greater than 25 MPa), and highpercent (%) elongation (greater than 250%). In addition, modulus can becontrolled across a broad range (1 to 100 MPa) by adjusting hard andsoft segment composition and displays a broad temperature insensitiveworking temperature range (approximately 250° C.). The system can beformulated into a two component mixture for practical applications.

The disclosure further provides a method for controlled synthesis of asegmented copolymer capable of displaying flexibility at lowtemperatures (down to −100° C.) and good mechanical properties. This isaccomplished through sequential addition of components to create analternating or segmented copolymer structure and compositional controlof hard and soft segments. In addition, chain length of the siloxanecomponent is beneficial to forming materials that show a temperatureindependent modulus down to −100° C. within an acceptable modulus range(1 to 100 MPa) for elastomeric materials. The disclosed compositionsdiffer from known compositions in the fact that thepolysiloxane-urethane/urea segmented copolymer compositions disclosedherein do not require an intermediate polyether segment to producehigher mechanical performance. This simplifies synthetic preparation ofthe system and creates a single low and sharp glass transition at lowtemperature (less than −100° C.) with a broad temperature insensitivemodulus or working temperature range (ΔT of approximately 250° C.). Thecopolymer compositions disclosed herein have properties that displayboth high tensile strength combined with low Tg.

FIG. 6 is a graph 22 showing modulus versus temperature comparisonsbetween one of the embodiments of the segmented copolymer of thedisclosure and known segmented copolymers containing polypropylene oxide(PPO). FIG. 6 shows a comparison of a siloxane urethane/urea segmentedcopolymer with and without an intermediate PPO interface. The legendshows compositional information for each sample in the form ofsiloxane/polyether/diisocyanate/chain extender [PDMS5.6k=dihydroxyalkylterminated polydimethyl siloxane Mn=5600, PPO2k=diamine terminatedpolypropylene oxide Mn=2000, HMDI=4,4′-methylenebis(cyclohexylisocyanate), DAC=1,2-diaminocyclohexane], molar ratio of the respectivecomponents, hard segment content by weight, and polypropylene oxidecontent by weight. Plot line 26 shows Example 1 with 0% PPO and a hardsegment content (HS %) of 24% by weight. The elongation of this materialwas found to be 473% with a true tensile strength of 48 MPa. The modulusversus temperature profile of this sample that does not contain apolyether segment was relatively flat between the temperature range−100° C. and 150° C. Plot line 28 shows a sample containing 22% PPO byweight and a HS % of 18% by weight. This sample possessed an elongationof 691% and a true tensile strength of 20 MPa and gave a modulus at roomtemperature roughly equivalent to that shown in plot line 26 without apolyether segment. However, there was a clear dependence of modulus ontemperature seen by the fact that the material steadily softened withincreased temperature and eventually began to flow at 150° C. Astemperature was lowered from ambient, the glass transition temperaturefrom the polyether was evident around −50° C. rapidly stiffening thematerial to show a modulus over 100 MPa. Plot line 24 shows a samplecontaining 33% PPO by weight and a HS % of 22% by weight. This increasein the amount of PPO and hard segment content increased the mechanicalproperties to give a % elongation of 892% with a true tensile strengthof 70 MPa. However, they served to stiffen the material at roomtemperature while increasing the glass transition to −40° C. compared tothe sample with less PPO content but still softening considerably withrising temperature. The siloxane segmented urea/urethane examples shownhere with an interfacial polyether segment and incorporating thecycloalkyl DAC as chain extender produced a significant improvement inmechanical properties over known methods. However, they also clearlydemonstrated the inability of known materials to perform as flexibleelastomeric materials at low temperatures (less than (<) −60° C.) due tothe glass transition behavior from the polyether component.

FIG. 7 is a graph 30 showing modulus (E′ (MPa)) versus temperature(degrees Celsius (C)) comparisons between segmented copolymers withdiffering siloxane block lengths. Influence of siloxane chain lengthsegments of the modulus versus temperature profile are shown in FIG. 7.The legend shows compositional information for each sample in the formof siloxane/diisocyanate/chain extender [PDMSx.xk=dihydroxyalkylterminated polydimethyl siloxane Mn=xx00 (i.e PDMS5.6k=Mn=5600),HMDI=4,4′-methylenebis(cyclohexyl isocyanate),DAC=1,2-diaminocyclohexane], molar ratio of the respective components,hard segment content by weight. Plot line 32 shows PDMS 2.5k. Plot line34 shows PDMS 2.5k and 29% HS %. Both of these samples used siloxanesoft segment components that were roughly half the size of the Mn=5600chains used in plot line 36 (Example 1). The influence this had onmodulus was dramatic in that for higher hard segment content (plot line32), the modulus was increased an order of magnitude to above 100 MPa,while for lower hard segment content (plot line 34) there was anoticeable dependence on modulus with temperature. Plot line 36 showsExample 1 PDMS 5.6k and 24% HS %. Plot line 38 shows PDMS 10k and 26% HSwhich possessed a siloxane soft segment component roughly twice as largeas the PDMS Mn=5600 component. This produced a modulus versustemperature profile similar to plot line 36 (Example 1) above roomtemperature. However, below −40° C. there was a large increase inmodulus due to crystallization of the longer PDMS segments. This seriesof samples demonstrated that there was a range of acceptable chainlengths for the di-functional siloxane soft segment component requiredto achieve the desired properties including a preferred modulus ofapproximately 10 MPa, a broad insensitive modulus versus temperatureprofile, and high tensile strength and elongation.

FIG. 8 is a graph 40 showing modulus versus temperature dynamicmechanical analysis data for Examples 1-4 of the disclosure. All samplesdisplayed modulii between 10 and 100 MPa at room temperature along witha broad flat modulus versus temperature profile between −100° C. and150° C. Plot line 48 shows the dynamic mechanical analysis forExample 1. Plot line 46 shows the dynamic mechanical analysis forExample 2. Plot line 42 shows the dynamic mechanical analysis forExample 3. Plot line 44 shows the dynamic mechanical analysis forExample 4.

Many modifications and other embodiments of the disclosure will come tomind to one skilled in the art to which this disclosure pertains havingthe benefit of the teachings presented in the foregoing descriptions andthe associated drawings. The embodiments described herein are meant tobe illustrative and are not intended to be limiting or exhaustive.Although specific terms are employed herein, they are used in a genericand descriptive sense only and not for purposes of limitation.

What is claimed is:
 1. A method of synthesizing and using a segmentedcopolymer comprising: mixing one or more α,ω (alpha, omega) amine or α,ω(alpha, omega) hydroxyl terminated polysiloxane first soft segmentshaving an average molecular weight of between about 2500 grams per moleto about 10,000 grams per mole, and one or more diisocyanate species,together to form a first reaction product; mixing the first reactionproduct, and one or more low molecular weight diol or diamine chainextenders each having an average molecular weight of less than 400 gramsper mole, together in a solvent to form a segmented copolymer insolution, wherein the solvent is a secondary or tertiary alcohol ofisopropanol; tert-butanol; 2-butanol; 3-methyl-3-pentanol;2-methyl-2-pentanol; t-amyl methyl ether; 2,3 dimethyl-2-butanol;3-methyl-1,3-butanediol; 2-3 dimethyl-3-pentanol; 3-ethyl-3-pentanol;2,4-dimethyl-2-pentanol; or 2-methyl-2-hexanol; and applying thesegmented copolymer in solution to one or more surfaces via spraycoating directly from the solution with the segmented copolymer, whereinthe segmented copolymer formed has a high flexibility at anenvironmental temperature of down to about −100 degrees Celsius, andfurther has a percent elongation of greater than about 250%, a hightensile strength of greater than about 25 MPa (megapascals), and asingle low glass transition temperature (Tg) in a range of from about−60 degrees Celsius to about −110 degrees Celsius.
 2. The method ofclaim 1, further comprising after forming the first reaction product,mixing the first reaction product with a solution of one or more secondsoft segments, wherein the one or more soft segments isperfluoropolyether; α,ω (alpha, omega) dihydroxy terminated fluoroether;α,ω (alpha, omega) hydroxyl terminated poly(perfluoromethylisopropylether); polythiodifluoromethylene; polybutadiene;polydioxypropylphosphazene; polydioxyethylphosphazene;polyoxytrimethylene; polydioxymethylphosphazene; polyisoprene; orpolyisobutylene.
 3. The method of claim 1, wherein the first reactionproduct and the solution of chain extenders are separately dissolved ina solvent prior to being mixed together.
 4. The method of claim 1,wherein the one or more α,ω (alpha, omega) amine or α,ω (alpha, omega)hydroxyl terminated polysiloxane first soft segments ispolydimethylsiloxane; poly(diphenyl-co-dimethylsiloxane);poly(methyl-3,3,3-trifluoropropylsiloxane);poly(methyl-n-octylsiloxane); poly(di-n-pentylsiloxane);poly(methyl-n-hexylsiloxane); poly(di-n-propylsiloxane);poly(methyl-n-pentylsiloxane); poly(methyl-n-butylsiloxane);poly(di-n-butylsiloxane); poly(methyl-n-propylsiloxane);poly(methylethylsiloxane); poly(methylhydridosiloxane); orpolydiethylsiloxane.
 5. The method of claim 1, wherein the one or morediisocyanate species is 4,4′-methylenebis(cyclohexyl isocyanate) (HMDI);cycloalkyl based diisocyanates; tolylene-2,4-diisocyante (TDI);4,4′-methylenebis(phenyl isocyanate) (MDI); or isophorone diisocyanate(IDI).
 6. The method of claim 1, wherein the one or more diol or diaminechain extenders is linear diamines; cycloalkyl diamines; cycloaliphaticdiamines; aromatic diamines; 1,2-diaminocyclohexane (DAC);1,3-diaminocyclohexane; 1,4-diaminocyclohexane; diethyltoluenediamine(DETDA); isophorone diamine (5-amino-1,3,3-trimethylcyclohexanemethanamine); bis-(p-aminocyclohexyl)methane;2,2-bis(4-aminocyclohexyl)propane; 4-methyl-1,3-cyclohexane diamine;2,4-diethyl-6-methylcyclohexane-1,3 diamine; or a mixture of two or morethereof.
 7. A method of synthesizing and applying to a surface asegmented copolymer comprising: mixing one or more α,ω (alpha, omega)amine or α,ω (alpha, omega) hydroxyl terminated polysiloxane first softsegments having an average molecular weight of between about 2500 gramsper mole to about 10,000 grams per mole, and one or more diisocyanatespecies, together to form a first reaction product, wherein the one ormore polysiloxane first soft segments is present in an amount of fromabout 40% by weight to about 95% by weight, based on a total weightpercent of the composition; and mixing the first reaction product, andone or more low molecular weight diol or diamine chain extenders eachhaving an average molecular weight of less than 400 grams per mole,together in a solvent to form a segmented copolymer in solution, whereinthe solvent is a secondary or tertiary alcohol of isopropanol;tert-butanol; 2-butanol; 3-methyl-3-pentanol; 2-methyl-2-pentanol;t-amyl methyl ether; 2,3 dimethyl-2-butanol; 3-methyl-1,3-butanediol;2-3 dimethyl-3-pentanol; 3-ethyl-3-pentanol; 2,4-dimethyl-2-pentanol; or2-methyl-2-hexanol, and wherein the solvent is not removed and thesegmented copolymer remains in solution for subsequent use; and usingthe segmented copolymer in solution by applying the segmented copolymerin solution to the surface via spray coating directly from the solutionwith the segmented copolymer, wherein the segmented copolymer formed hasa high flexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.8. A method of synthesizing and using a segmented copolymer comprising:mixing one or more α,ω (alpha, omega) amine or α,ω (alpha, omega)hydroxyl terminated polysiloxane first soft segments having an averagemolecular weight of between about 2500 grams per mole to about 10,000grams per mole, and one or more diisocyanate species, together to form afirst reaction product, wherein the one or more polysiloxane first softsegments is present in an amount of from about 40% by weight to about95% by weight, based on a total weight percent of the composition;mixing the first reaction product and one or more perfluoropolyethersecond soft segments together to form a second reaction product; mixingthe second reaction product and one or more low molecular weight diol ordiamine chain extenders each having an average molecular weight of lessthan 400 grams per mole, together in a solvent to form a segmentedcopolymer in solution; and applying the segmented copolymer in solutionto one or more surfaces via spray coating directly from the solutionwith the segmented copolymer, wherein the segmented copolymer formed hasa high flexibility at an environmental temperature of down to about −100degrees Celsius, and further has a percent elongation of greater thanabout 250%, a high tensile strength of greater than about 25 MPa(megapascals), and a single low glass transition temperature (Tg) in arange of from about −60 degrees Celsius to about −110 degrees Celsius.9. The method of claim 8, wherein the second reaction product and thesolution of chain extenders are separately dissolved in a solvent priorto being mixed together.
 10. The method of claim 8, wherein the solventis a secondary or tertiary alcohol of isopropanol; tert-butanol;2-butanol; 3-methyl-3-pentanol; 2-methyl-2-pentanol; t-amyl methylether; 2,3 dimethyl-2-butanol; 3-methyl-1,3-butanediol; 2-3dimethyl-3-pentanol; 3-ethyl-3-pentanol; 2,4-dimethyl-2-pentanol; or2-methyl-2-hexanol.
 11. The method of claim 8, wherein the one or moreα,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxyl terminatedpolysiloxane first soft segments is polydimethylsiloxane;poly(diphenyl-co-dimethylsiloxane);poly(methyl-3,3,3-trifluoropropylsiloxane);poly(methyl-n-octylsiloxane); poly(di-n-pentylsiloxane);poly(methyl-n-hexylsiloxane); poly(di-n-propylsiloxane);poly(methyl-n-pentylsiloxane); poly(methyl-n-butylsiloxane);poly(di-n-butylsiloxane); poly(methyl-n-propylsiloxane);poly(methylethylsiloxane); poly(methylhydridosiloxane); orpolydiethylsiloxane.
 12. The method of claim 8, wherein the one or morediisocyanate species is 4,4′-methylenebis(cyclohexyl isocyanate) (HMDI);cycloalkyl based diisocyanates; tolylene-2,4-diisocyante (TDI);4,4′-methylenebis(phenyl isocyanate) (MDI); or isophorone diisocyanate(IDI).
 13. The method of claim 8, wherein the one or more diol ordiamine chain extenders is linear diamines; cycloalkyl diamines;cycloaliphatic diamines; aromatic diamines; 1,2-diaminocyclohexane(DAC); 1,3-diaminocyclohexane; 1,4-diaminocyclohexane;diethyltoluenediamine (DETDA); isophorone diamine(5-amino-1,3,3-trimethyl cyclohexanemethanamine);bis-(p-aminocyclohexyl)methane; 2,2-bis(4-aminocyclohexyl)propane;4-methyl-1,3-cyclohexane diamine; 2,4-diethyl-6-methylcyclohexane-1,3diamine; or a mixture of two or more thereof.
 14. The method of claim 8,wherein the one or more perfluoropolyether second soft segments is α,ω(alpha, omega) dihydroxy terminated fluoroether and/or α,ω (alpha,omega) hydroxyl terminated poly(perfluoromethylisopropyl ether.
 15. Amethod of synthesizing and using a segmented copolymer comprising:mixing one or more α,ω (alpha, omega) amine or α,ω (alpha, omega)hydroxyl terminated polysiloxane first soft segments having an averagemolecular weight of between about 2500 grams per mole to about 10,000grams per mole, and one or more diisocyanate species, together to form afirst reaction product; mixing the first reaction product and one ormore second soft segments together to form a second reaction product,wherein the one or more second soft segments is perfluoropolyether; α,ω(alpha, omega) dihydroxy terminated fluoroether; α,ω (alpha, omega)hydroxyl terminated poly(perfluoromethylisopropyl ether);polythiodifluoromethylene; polybutadiene; polydioxypropylphosphazene;polydioxyethylphosphazene; polydioxymethylphosphazene; polyisoprene; orpolyisobutylene; mixing the second reaction product, and one or morediamine chain extenders each having an average molecular weight of lessthan 400 grams per mole, together in a solvent to form a segmentedcopolymer in solution, wherein the one or more diamine chain extendersis isophorone diamine (5-amino-1,3,3-trimethyl cyclohexanemethanamine);bis-(p-aminocyclohexyl)methane; 2,2-bis(4-aminocyclohexyl)propane;4-methyl-1,3-cyclohexane diamine; 2,4-diethyl-6-methylcyclohexane-1,3diamine; or a mixture of two or more thereof; and applying the segmentedcopolymer in solution to one or more surfaces via spray coating directlyfrom the solution with the segmented copolymer, wherein the segmentedcopolymer formed has a high flexibility at an environmental temperatureof down to about −100 degrees Celsius, and further has a percentelongation of greater than about 250%, a high tensile strength ofgreater than about 25 MPa (megapascals), and a single low glasstransition temperature (Tg) in a range of from about −60 degrees Celsiusto about −110 degrees Celsius.
 16. The method of claim 15, wherein theone or more α,ω (alpha, omega) amine or α,ω (alpha, omega) hydroxylterminated polysiloxane first soft segments is polydimethylsiloxane;poly(diphenyl-co-dimethylsiloxane);poly(methyl-3,3,3-trifluoropropylsiloxane);poly(methyl-n-octylsiloxane); poly(di-n-pentylsiloxane);poly(methyl-n-hexylsiloxane); poly(di-n-propylsiloxane);poly(methyl-n-pentylsiloxane); poly(methyl-n-butylsiloxane);poly(di-n-butylsiloxane); poly(methyl-n-propylsiloxane);poly(methylethylsiloxane); poly(methylhydridosiloxane); orpolydiethylsiloxane.
 17. The method of claim 15, wherein the secondreaction product and the solution of chain extenders are separatelydissolved in a solvent prior to being mixed together.
 18. The method ofclaim 15, wherein the one or more diisocyanate species is4,4′-methylenebis(cyclohexyl isocyanate) (HMDI); cycloalkyl baseddiisocyanates; tolylene-2,4-diisocyante (TDI); 4,4′-methylenebis(phenylisocyanate) (MDI); and/or isophorone diisocyanate (IDI).
 19. A method ofsynthesizing and applying to a surface a segmented copolymer comprising:mixing one or more α,ω (alpha, omega) amine or α,ω (alpha, omega)hydroxyl terminated polysiloxane first soft segments having an averagemolecular weight of between about 2500 grams per mole to about 10,000grams per mole, and one or more diisocyanate species, together to form afirst reaction product; mixing the first reaction product with asolution of one or more second soft segments, wherein the one or moresoft segments is perfluoropolyether; α,ω (alpha, omega) dihydroxyterminated fluoroether; α,ω (alpha, omega) hydroxyl terminatedpoly(perfluoromethylisopropyl ether); polythiodifluoromethylene;polybutadiene; polydioxypropylphosphazene; polydioxyethylphosphazene;polyoxytrimethylene; polydioxymethylphosphazene; polyisoprene; orpolyisobutylene; mixing the first reaction product, and one or more lowmolecular weight diol or diamine chain extenders each having an averagemolecular weight of less than 400 grams per mole, together in a solventto form a segmented copolymer in solution, wherein the solvent is asecondary or tertiary alcohol of isopropanol; tert-butanol; 2-butanol;3-methyl-3-pentanol; 2-methyl-2-pentanol; t-amyl methyl ether; 2,3dimethyl-2-butanol; 3-methyl-1,3-butanediol; 2-3 dimethyl-3-pentanol;3-ethyl-3-pentanol; 2,4-dimethyl-2-pentanol; or 2-methyl-2-hexanol; andapplying the segmented copolymer in solution to the surface via spraycoating directly from the solution with the segmented copolymer, whereinthe segmented copolymer formed has a high flexibility at anenvironmental temperature of down to about −100 degrees Celsius, andfurther has a percent elongation of greater than about 250%, a hightensile strength of greater than about 25 MPa (megapascals), and asingle low glass transition temperature (Tg) in a range of from about−60 degrees Celsius to about −110 degrees Celsius.